Given a 2d grid map of '1's (land) and '0's(water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.

Remember the story of Little Match Girl? By now, you know exactly what matchsticks the little match girl has, please find out a way you can make one square by using up all those matchsticks. You should not break any stick, but you can link them up, and each matchstick must be used exactly one time.

Your input will be several matchsticks the girl has, represented with their stick length. Your output will either be true or false, to represent whether you could make one square using all the matchsticks the little match girl has.

Example 1:

Input: [1,1,2,2,2]Output: trueExplanation: You can form a square with length 2, one side of the square came two sticks with length 1.

Example 2:

Input: [3,3,3,3,4]Output: falseExplanation: You cannot find a way to form a square with all the matchsticks.

Given a list of words (without duplicates), please write a program that returns all concatenated words in the given list of words.A concatenated word is defined as a string that is comprised entirely of at least two shorter words in the given array.

Example:

12345

Input:["cat","cats","catsdogcats","dog","dogcatsdog","hippopotamuses","rat","ratcatdogcat"]Output: ["catsdogcats","dogcatsdog","ratcatdogcat"]Explanation: "catsdogcats" can be concatenated by "cats", "dog" and "cats"; "dogcatsdog" can be concatenated by "dog", "cats" and "dog"; "ratcatdogcat" can be concatenated by "rat", "cat", "dog" and "cat".

Note:

The number of elements of the given array will not exceed 10,000

The length sum of elements in the given array will not exceed 600,000.

All the input string will only include lower case letters.The returned elements order does not matter.

Given a 2d grid map of '1's (land) and '0's(water), count the number of islands. An island is surrounded by water and is formed by connecting adjacent lands horizontally or vertically. You may assume all four edges of the grid are all surrounded by water.